Baseline characteristics of study patients
| Characteristic | Sterile % total (n=747) | Non-sterile % total (n=733) |
| Age, year, mean±SD | 39.2 (±16.5) | 39.5 (±16.9) |
| Sex | ||
| Male | 74.2 | 73.0 |
| Use of antibiotics | ||
| None | 96.4% | 96.3% |
| Oral antibiotics | 0.8% | 1.0% |
| Topical antibiotics | 0.0% | 0.1% |
| Unknown | 2.8% | 2.6% |
| Use of oral antidiabetics | ||
| No | 92.9% | 90.9% |
| Yes | 1.1% | 2.6% |
| Unknown | 6.0% | 6.5% |
| Use of insulin | ||
| No | 95.7% | 96.6% |
| Yes | 0.9% | 1.0% |
| Unknown | 3.3% | 2.5% |
| Use of immunosuppressants | ||
| No | 96.1% | 95.2% |
| Yes | 1.1% | 2.3% |
| Unknown | 2.8% | 2.5% |
| Use of corticosteroids | ||
| No | 95.2% | 94.3% |
| Yes | 1.2% | 2.3% |
| Unknown | 3.6% | 3.4% |
| Smokers | ||
| No | 56.1% | 58.0% |
| Yes | 34.0% | 33.6% |
| Unknown | 9.9% | 8.5% |